Can deer smell it on your breath? Can they smell it on the ground from downwind and does it spook them?

I have heard many arguments about this between my hunting buddies (one of which is a registered Maine Guide.)

He argues that he would shoot me out of my stand when I hunt with him if he saw me dipping (chewing.)

His son thinks that he's full of it. He shot a few deer with a mouthful of chew in.

Our good friend sat on his property last year with a cigarette in his mouth, on his cell phone, with a beer between his legs and low and behold had to end the call early to shoot a 210lb. 9-pointer that walked up on him.